1. Field
Embodiments of the invention relate generally to a light emitting device and a method for manufacturing the same, a lighting fixture, and a lighting system.
2. Background Art
Use of semiconductor light emitting elements in light emitting devices and lighting fixtures facilitates energy saving, lifetime extension, downsizing, and weight saving. Furthermore, it is also desirable to the environment because of no use of mercury and the like.
Therefore, there are increasing demands for small size, low profile, and light weight in applications such as headlights and other illumination devices and backlights of liquid crystal display devices.
JP-A 2006-106212 (Kokai) discloses an example technique for a backlight unit satisfying the reduction of power consumption and the enhancement of luminance. The backlight unit disclosed in this example includes light sources for emitting, respectively, red light, blue light, and green light, a first reflector for reflecting the light from the light sources toward an opening, and a second reflector for reflecting the light from the light sources to the other end of the housing.
In general, a surface-emitting element like LED chip emits light with a wide light distribution angle upward above its surface. To obtain higher luminance of the light output from the surface-emitting element with a wide light distribution angle, it is necessary to collect and collimate the light using a large lens and the like. Also, it is necessary to use a larger-size element because current density applied to the element must be reduced for higher brightness operation. In this example, the total emitting size of the three-color (RGB) surface-emitting light sources becomes much larger. Therefore, the collecting and collimating lens is much larger as well. Thus, this example does not sufficiently satisfy the requirements of high luminance and optical system downsizing at the same time.